A preliminary search has been made and the following patents uncovered in Class 111, Subs. 4, 72, 89 and 94:
______________________________________ 382,069 1,563,625 4,218,981 557,483 2,865,315 4,267,782 1,238,576 3,249,034 1,439,601 3,797,412 ______________________________________
None of the foregoing patents disclose the details of the present invention; for instance U.S. Pat. Nos. 382,069 and 557,483 are merely posthole diggers with no means to close the hole dug thereby.
U.S. Pat. No. 1,238,576 shows a dibble and an attached conical-shaped trough to place the soil around the plant and then force the trough adjacent the original hole to "throw the dirt around the roots within the hole", this requiring careful aim.
U.S. Pat. No. 1,439,601 is a marking device to locate the next planting hole. It appears to actually make a hole for seeds. The marking device is adjustable.
U.S. Pat. No. 1,563,625 is a spring-loaded dibble so that the dibble is raised and then a seedling is dropped in alignment to the dibble. It has a single spring-loaded pressure device to press the earth into one side of the hole but not completely around the seedling.
U.S. Pat. No. 2,865,315 has a semi-circular, pointed end steel bill having a pivotal member lying against the bill which is moved outwardly to allow the garlic, onion flower or bulb to reach the bottom of the hole dug by the bill. No means are provided to completely cover the hole.
U.S. Pat. No. 3,797,412 has a pair of jaws like U.S. Pat. No. 2,865,315 wherein one jaw is movable outwardly. It does not disclose any means for closing the hole.
U.S. Pat No. 4,218,981 is similar to U.S. Pat. No. 1,563,625 except it has no dibble and no springs but has a marker for the next seed and has no means to cover the hole made by the dibble.
U.S. Pat. No. 4,267,792 is a watering device to make a hole in the ground, and that is all.